(19)

(11)

EP 1 121 714 A1

(12)

(43) Date of publication: 08.08.2001 Bulletin 2001/32 (21) Application number: 99949628.4 (22) Date of filing: 24.09.1999

(51) International Patent Classification (IPC)7: H01L 21/311 (86) International application number: PCT/US9920/888 (87) International publication number: WO 0019/506 (06.04.2000 Gazette 2000/14)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 30.09.1998 US 163301 (71) Applicant: LAM RESEARCH CORPORATION Fremont, CA 94538-6470 (US)	(72) Inventors: ZHU, Helen Milpitas, CA 95035 (US) LINDQUIST, Roger, F. Campbell, CA 95008 (US) (74) Representative: Barnard, Eric Edward  Brookes Batchellor102-108 Clerkenwell Road London EC1M 5SA London EC1M 5SA (GB)